Relative 'value' of old models


It is puzzling to see that the HP65 has a higher monetary value than the HP10 (this is an example).

Actually, many die-hard HP fans have the 65 while they are still searching for a 10.

What gives ? In this case, the items are relatively comparable : both are calculators, from the same maker, about same time frame. Obviously the feature set is wildly different.

I'd say that whatever is rare, mechanically, fetches higher price (because I can easily exchange it for the more common model).

Your thoughts ?


Who, other than a collector in search of completeness, would really want an HP-10? LED-equipped with batteries to maintain and repair; a function set more limited than a modern $10 drugstore special.

Of course, I will admit that the highest price I've paid (by a modest margin) for an HP calc is for a clean 10C, even though I could have had another 15C in comparable condition for the same price.

-- KS


I think many hybrids "Users" and "Collectors" do appreciate elegance & simplicity along WITH usability.

Maybe that's why Hp models that match this pattern : Hp80, Hp10C, Hp25C, Hp65... are quite sought after.

These models do the requested job, not more, not less.

For example, I use a different calc every day but I'm always a little bit reluctant on the "Hp-67 day" (cluttered keyboard) "Hp-15C day" (What did I program for key A ?).

Of course, rarity is also a factor for collectors but you'll have to use Taylor's series on an Hp10A to estimate a function...and it could be long...




Interesting! Another afficionado who does the same like me: Nearly every day I rotate the use of my hp collection (only LCD models). But I also have the same nice days (32SII) and not so good days (15C) and worst days (17BII)...

...simplicity AND usability. Yes, for my better models it IS exactly the formula because I even had begun buying (collecting?) usable calculators.



Hi Valentino !

I do enjoy rotation !

Here is my scheme :

Business days :

I also use my Hp-71B at work.

Week-ends :
41C/CV,CX (including blanknut)

Special days, Xmas, Easter day : 19C

I don't have an Hp-10A because I don't consider it as a calculator but as a mistake ;-)

Could you please give details on your daily choices ?

Thanks & cheers from France !



Some weeks ago, I tried to do the same as you do: use a different calc every working day. Well, I've stepped back. After all, I found me looking for some plain and simple functions like square roots or 1/x on the various keyboards of Voyagers and Pioneers, slowing down my calculations. And I had quite some difficulties to remember in which menu the needed function is hidden in the "calc of the day".

So I now have my HP11C with me for everyday use.

Returning to the question of GE: esthetically, I like the Woodstocks best - best keys, solid housing, compact design, nice feeling - BUT limited operation time, small set of functions, little space for programs and cryptic coding of program steps. So this form factor combined with today's technology would be nice. Until then, I collect some calcs for their beauty, some for their elegance and some for their features (i.e. useability).

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